[HDFS-8469] Lockfiles are not being created for datanode storage directories

• Type: Bug
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.4.0
• Component/s: datanode
• Assignee: Colin McCabe
• Reporter: Colin McCabe
• Created: 22/May/15 18:54
• Updated: 06/Jan/17 22:02

Description

Lockfiles are not being created for datanode storage directories. Due to a mixup, we are initializing the StorageDirectory class with shared=true (an option which was only intended for NFS directories used to implement NameNode HA). Setting shared=true disables lockfile generation and prints a log message like this:

2015-05-22 11:45:16,367 INFO  common.Storage (Storage.java:lock(675)) - Locking is disabled for /home/cmccabe/hadoop2/hadoop-hdfs-project/hadoop-hdfs/target/  test/data/dfs/data/data5/current/BP-122766180-127.0.0.1-1432320314834

Without lock files, we could accidentally spawn two datanode processes using the same directories without realizing it.

Issue Links

• is broken by: HDFS-5138 Support HDFS upgrade in HA